When the fuel flow in a fuel cell that is electrically connected to electronic equipment is stopped, electric power gradually decreases to a point at which power generation stops. In this manner, the electric power decreases below a threshold necessary to drive the electronic equipment at a certain time. As a result, some of the electric power that is generated by the cell is wasted.
In view of such a problem, Japanese Laid-Open Patent Application (JP-A) 2005-158298 discloses a method for operating a fuel cell power generating system in which an external circuit is interrupted together with the stoppage of the fuel gas flow. However, this operating method requires an operation control means for simultaneously stopping the flow of the fuel gas and interrupting the external circuit.
JP-A 2004-71262 discloses a fuel cell device in which the actuation control is effected on the basis of a result of mounting recognition during the mounting of a fuel cartridge, which is provided with a memory, to the fuel cell device. However, this fuel cell device requires a control portion for effecting the control based on the recognition of the mounting of the fuel cartridge to the fuel cell device.
As described above, when the method of JP-A 2005-158298 and the device of JP-A 2004-71262 are put into practical use, it is necessary to employ a control circuit to detect a complicated electric signal and to control fuel flow and external circuit interruption based on the detection. Accordingly, it is difficult to reduce both the size and the cost of the fuel cell.